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HEAT NSJLAYED RECEPTACLE vJ'WPLicAmN FILED F5310. 1919. y

Plum-ed June 3, 19m.

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EARL W. JOHNSTON, 0F DETROIT, MICHGA'N.

HEAT-INSULATED RECEETACLE.

Specication of Letters Patent.

Patented lune Italia.

Application led February 20, 1919. Serial No. 278,243.

To uit `folto/n it may concern.'

13e it known that I, EARL W. JOHNSTON, citizen of the United States,residing at 16 lV. Elizabeth St.. Detroit, in the county o lVayne andState of Michigan, have invent-ed certain new and useiul improvements inHeat-insulated Receptacles, of which the Jfollowing' is a specication.

This invention relates to heat insulated receptacles, particularly to avessel adapted for use as a reless cooker, or in other relations when itis desired to retain its contents at a desiredtemperature.

The device comprises a receptacle having double walls, separated by avacuum space. The vessel may be made ol porcelain or similar niaterial,the body being cast in one piece and the cover in another piece, with aclose joint between the two. improved means are provided for permittingthe air to be exhausted from the space between the walls, said meanscomprising a valve and a valve seat oi novel construction, suitable forthe purpose of receiving the mouth of an air pump for drawing the vacuumin the wall.

In the accompanying drawings Figure l is a halt section and elevationot' the vessel. Fig. 2 is an enlarged detail showing` the valvestructure and the Inanner oi applying an air pump thereto.

rl`he body of the vessel comprises an outer wall l. and an inner wall 2,with a vacuum space 3, therebetween, the walls being connected at thetop by a cross wall 8, which forms the seat for the lid or cover. Thislid is also hollow, having an outer wall 9, and an inner wall l0, with avacuum space 11, therebetween. The cover may be provided with lugs 19.,to receive a handle, and it lits with a close joint at 15 upon the rimof the body. These parts are preferably molded, each in a single space,of porcelain or other vitreous material.

The body and cover are each provided with `valves, through which air mayhe ern hausted from the vacuum space. This valve comprises a seat pieceor ring '16, made of metal, the margin of the central opening he,- ingupset, or struck up inwardly, as indicated 1n '16, to form a taperedneck or funnel shaped passage adapted to receive a conical valve plug17. Theonter. edge of the margin of this seat iece is embedded in thematerial of the wal. in which the valve is set, and consequently isheldsealed thereby,

von the exhaust stroke and will seat on the return, and, as stated,after the removal of the pump, the exterior air pressure will hold theplu g' closed against the tapered seat, and preserve'-the vacuum withinthe wall for an indefinite period. 'if he vacuum can again be drawn bythe use of the pump', whenever necessary. 0r the valve 17, can, besoldered in its closed position, to per manently seal the same, themetal valve seat and valve plug permitting this action.

A vessel so made of porcelain may be enameled, and will be practicallyair-tight and non-porous, and when the walls are made suilciently thick,will support themlselves and require no internal bracing.

This vacuum space prevents the loss of heat in the usual manner, and theabsence of any intervening support and braces reduces the comluctingarea to a minin'nnn.

l claim:

l. A double walled vessel' made of molded material and having a vacuumspace within they same. one of the walls being provided with a valvecomprising a metal seat,`the outer edge of which is molded and embeddedin the wall. and a plug cooperating with said seat.

2. A double walled vessel made of molded material with a vacuum spacebetween the walls. and a valve comprising a metal disk, the outer ede'eoi which is molded and ernbedded in the vail and the inner edge of whichis upset inwardly to `form a tapered neck, and a tapered plug fitting insaid neck.

In testimony whereof, aiix my signature in presence of two Witnesses.

EARL W. JOHNSTON.

Witnesses:

ARTHUR L.; BROWN, EDWIN H. Korean..

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